Density Measurement of Thin Sputtered Carbon Films

1988 ◽  
Vol 32 ◽  
pp. 323-330 ◽  
Author(s):  
G. L. Gorman ◽  
M.-M. Chen ◽  
G. Castillo ◽  
R. C. C. Perera
Keyword(s):  
Carbon Film ◽  
Processing Condition ◽  
Density Measurement ◽  
Practical Interest ◽  
Processing Parameters ◽  
Carbon Films ◽  
Nondestructive Method ◽  
Gas Pressure ◽  
X Ray ◽  
Thin Carbon

AbstractThe densities of sputtered thin carbon films have been determined using a novel X-ray technique. This nondestructive method involves the measurement of the transmitivity of a characteristic soft (low energy) X-ray line through the carbon film, and using the established equation I1 = I0eμpt where I1/I0 is the transmitivity, fi the photo absorption cross section, t the independently measured thickness, the density p can be easily solved for. This paper demonstrates the feasibility of using this simple technique to measure densities of carbon films as thin as 300 Å, which is of tremendous practical interest as carbon films on this order of thickness are used extensively as abrasive and corrosive barriers (overcoats) for metallic recording media disks. The dependence of the density upon film thickness for a fixed processing condition is presented, as also its dependence (for a fixed thickness) upon different processing parameters (e.g., sputtering gas pressure and target power). The trends noted in this study indicate that the sputtering gas pressure plays the most important role, changing the film density from 2.4gm/cm3 at 1 mTorr to 1.5gm/cm3 at 30 mTorr for 1000 Å thick films.

scholarly journals Optical emission spectroscopy of laser-produced carbon plasma at moderate and low irradiance in an ambient atmosphere

1995 ◽  
Vol 13 (4) ◽  
pp. 481-492 ◽  
Author(s):  
R.K. Thareja ◽  
Abhilasha ◽  
R.K. Dwivedi
Keyword(s):  
Carbon Film ◽  
Carbon Films ◽  
Moderate Intensity ◽  
Ambient Atmosphere ◽  
X Ray Diffraction ◽  
Argon Gas ◽  
X Ray ◽  
Double Peak Structure ◽  
Thin Carbon ◽  
Carbon Plasma

The plasma produced during pulsed-laser deposition of thin carbon films is studied in the presence of ambient gases (Air, He, Ar) at low and moderate irradiances of Nd:YAG laser. The presence of ambient gas shows a pronounced effect on the dynamics of the plasma plume. At moderate intensity, we report an appearance of a peculiar double-peak structure in the temporal profile of the C II transition in laser-produced carbon plasma as it expands into a background gas. We believe that the structure originates mainly due to stratification of the plasma into fast and slow ion components at the interface where Rayleigh-Taylor instability occurs. Thin carbon films deposited on silicon in the presence of argon gas have shown the characteristic features of diamond-like carbon in X-ray diffraction and Raman Spectroscopy. The X-ray diffraction pattern of carbon film deposited at 1 torr of argon gas pressure shows the dominance of (111), (220), (311), and (400) crystalline plane of cubic diamond.

Determination of Ultra-Thin Carbon Coating Thickness by X-ray Fluorescence Technique

1988 ◽  
Vol 32 ◽  
pp. 331-339
Author(s):  
R. L. White ◽  
T. C. Huang
Keyword(s):  
Film Thickness ◽  
Carbon Coating ◽  
Layer Structure ◽  
Carbon Film ◽  
Calibration Procedure ◽  
High Precision Measurement ◽  
X Ray ◽  
Thin Carbon ◽  
Counting Time

AbstractA tcchniquc for high-precision measurement of carbon thin-film thickness using X-ray fluorescence (XRF) is described. A quadratic calibration procedure is used for carbon thin films on silicon. Measurement of carbon-film thickness in a double-layer structure of carbon and CoCrX alloy is complicated by interference effects from the underlying layer. The dependence of the relative precision in measuring thickness (σT/T) on the counting time has been derived. It shows that a precision of 2% for a 25-nm carbon coating can be obtained using a W/C crystal and counting time of 4 minutes. Intensity and resolution advantages provided by the recently developed Ni/C and V/C multilayer synthetic crystals are also described.

Optimal Scanning Condition of Selective Laser Melting Processing with Stainless Steel 316L Powder

2011 ◽  
Vol 341-342 ◽  
pp. 816-820 ◽  
Author(s):  
Apinya Laohaprapanon ◽  
Pongnarin Jeamwatthanachai ◽  
Marut Wongcumchang ◽  
Nattapon Chantarapanich ◽  
Surapon Chantaweroad ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Selective Laser Melting ◽  
Visual Inspection ◽  
Processing Condition ◽  
Density Measurement ◽  
Scanning Speed ◽  
Processing Parameters ◽  
Stainless Steel 316L ◽  
Laser Melting ◽  
Optimal Processing

This study aimed to investigate the stainless steel 316L processing by means of selective laser melting (SLM). The processing parameters under consideration included laser power (25-225 W), scanning speed (50-320 mm/s), and scan spacing (0.04 and 0.06 mm). Every processing was constrained the layer thickness as of 100 µm. All parameters were performed based on two experiments, line scanning and multiple layers scanning. Each of final workpieces was examined by visual inspection, density measurement, hardness, and built rate. From the experiments, the optimal processing conditions which produced the smooth tracks were obtained. The workpiece processed by this optimal processing condition presented quality characteristics with 97.6% density and 220±6 HV hardness.

Ion Probe Diagnostics of Laser Ablated Plumes for Thin Carbon Films Deposition

1998 ◽  
Vol 12 (25) ◽  
pp. 2619-2633 ◽  
Author(s):  
R. K. Dwivedi ◽  
S. P. Singh ◽  
R. K. Thareja
Keyword(s):  
Film Growth ◽  
Pulsed Laser ◽  
Target Surface ◽  
Carbon Films ◽  
Gas Pressure ◽  
Plasma Parameters ◽  
Ion Probe ◽  
Thin Carbon ◽  
Ambient Gas ◽  
Deposited Film

The propagation of the carbon plumes in argon atmosphere used for film growth by pulsed laser ablation deposition (PLAD) is studied using ion probe. Spatial and angle resolved analysis of plasma parameters as a function of argon gas pressure is presented. The electron temperature is strongly dependent on the angle with target surface normal as well as the distance from the target surface. The forward directed nature of the PLAD process is strongly influenced by the pressure of the ambient gas. The plasma parameters are used to explain the effect of ambient gas pressure on the characteristics of the deposited film.

Effects of Amorphous Carbon Films on the Performance of Porous Silicon Electroluminescence

2002 ◽  
Vol 737 ◽  
Author(s):  
Bernard Gelloz ◽  
Nobuyoshi Koshida
Keyword(s):  
Porous Silicon ◽  
Amorphous Carbon ◽  
Chemical Stability ◽  
Indium Tin Oxide ◽  
Carbon Film ◽  
Carbon Films ◽  
Positive Effects ◽  
Thin Carbon ◽  
Thin Carbon Film ◽  
The Stability

ABSTRACTEfficient electroluminescence (EL) is obtained at low operating voltages (<3 V) from n+-type silicon- electrochemically oxidized thin nanocrystalline porous silicon (PS)-amorphous carbon-Indium tin oxide (ITO) junctions. The effects of a few nanometer thick amorphous carbon film between PS and ITO on the EL characteristics have been investigated. The carbon film enhances the stability. The EL efficiency is improved due to a reduction of current density and an increase in EL intensity. In addition, the reproducibility from device to device is very much improved by the carbon film. The enhancement in stability should originate from the capping of PS by the carbon film and the high chemical stability of carbon and Si-C bonds, which should prevent PS oxidation. The carbon film acts as an efficient buffer layer between PS and ITO, resulting in enhanced mechanical, electrical and chemical stability of the top contact and providing high reproducibility. The thin carbon film has only positive effects on all the EL characteristics. This is a very important step towards application.

A New Method for Single Atom Specimen Preparation

1975 ◽  
Vol 33 ◽  
pp. 224-225
Author(s):  
W. Chiu ◽  
R. M. Glaeser ◽  
S. Prussin
Keyword(s):  
Unit Area ◽  
Carbon Film ◽  
Gold Atom ◽  
High Resolution Electron Microscopy ◽  
Carbon Films ◽  
Single Atom ◽  
Specimen Preparation ◽  
Electron Microscopic ◽  
Thin Carbon ◽  
Thin Carbon Film

A reliable method of confirming that one is able to produce single atom images in high resolution electron microscopy is to make a comparison of the number of atoms per unit area that is seen by the electron microscopic observations and the number per unit area as determined by a separate experimental technique of high accuracy. This report presents a method of preparinga specimen composed of a low distribution of gold atoms (ca. 1 atom/104 Å2) sandwiched between two ultra-thin carbon films, and also a method of measuring the gold atom density in the specimen by neutron activation analysis.The specimen was prepared by evaporation onto a freshly cleaved mica substrate in a vacuum evaporator, as shown in Figure 1. One side of the vacuum chamber was used to prepare a thin carbon film according to the method of Williams and Glaeser (1972), and the other side was used to evaporate the gold atoms from a molybdenum strip, which had a micro-quantity of gold deposited on a 1 cm2 surface area from a previous evaporation.

Thermal Degradation and Burnishing Wear of Thin Carbon Film by Frictional Heat Generation

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Sungae Lee ◽  
Muyang He ◽  
Chang-Dong Yeo
Keyword(s):  
Thermal Degradation ◽  
Heat Generation ◽  
Temperature Rise ◽  
High Speed ◽  
Carbon Film ◽  
Carbon Films ◽  
Frictional Heat ◽  
Frictional Heat Generation ◽  
Thin Carbon ◽  
Rough Surface Contact

The burnishing wear of carbon films found in dynamic microdevices could be attributed to both mechanical stress and temperature rise by frictional heat generation. In this study, novel modeling and experiment were performed to investigate the burnishing wear mechanism of carbon film during high speed sliding contact. An improved thermomechanical contact model for a single asperity was extended to rough surface contact. The contact stress and surface temperature rise were examined at various contact conditions. To verify the thermal degradation of the carbon film by frictional heat flux, micro-Raman spectroscopy measurement was performed on actual burnishing failure sample.

X-Ray Production and Second Harmonic Generation by Superintense Femtosecond Laser Pulses in the Solids with Restricted Thermal Conduction

1997 ◽  
Vol 06 (04) ◽  
pp. 495-505 ◽  
Author(s):  
V. G. Babaev ◽  
M. S. Dzhidzhoev ◽  
V. M. Gordienko ◽  
M. A. Joukov ◽  
A. B. Savel'ev ◽  
...  
Keyword(s):  
Electron Temperature ◽  
Thermal Conduction ◽  
Second Harmonic ◽  
Carbon Film ◽  
Laser Pulses ◽  
Carbon Films ◽  
Femtosecond Laser Pulses ◽  
X Ray ◽  
Observed Behaviour ◽  
Freely Suspended

Two new types of targets: ultrathin freely suspended carbon films and porous Si, both revealing thermoconductivity restriction leading to plasma overheating upto electron temperature above 1 keV under "moderate" intensities 1015 - 1016 W · cm-2 has been investigated experimentally. For the ultrathin carbon film of 20–30 nm X-ray yield threefold increase has been observed. Computer simulations decribe well the observed behaviour of the X-ray yield, and the electron temperature of 700 eV was deducted for the film of 10 nm in thickness. Por-Si produces greater X-ray flux under intensity of 1016 W · cm-2 as compared to the solid Si. If the intensity increased the total X-ray yield from por-Si undergoes "saturation", while the X-ray yield from solid Si fits as ≈ I2. Simple model to describe the "overheating" of Si plasma using a set of ultrathin films is developed. Some promising advantages of new targets are discussed.

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